China Unleashes $483 Billion to Stem the Market Rout

China has created what amounts to a state-run margin trader with $483 billion of firepower, its latest effort to end a stock-market rout that threatens to drag down economic growth and erode confidence in President Xi Jinping’s government.

China Securities Finance Corp. can access as much as 3 trillion yuan of borrowed funds from sources including the central bank and commercial lenders, according to people familiar with the matter. The money may be used to buy shares and provide liquidity to brokerages, the people said, asking not to be named because the information wasn’t public.